For efficiencies in the fabrication of an electronic device, electronic components of the device are often electrically and mechanically coupled to each other via a flexible printed circuit to form a flexible printed circuit module. The flexible printed circuit (FPC) module may be prefabricated and easily assembled as a module into the electronic device.
In fabricating the FPC module, it is desirable to decouple the yield loss of an expensive electronic component from an inexpensive electronic component. That way, a defective inexpensive electronic component will not result in loss of the entire FPC module including the expensive electronic component. It is therefore typical that each electronic component may be affixed to its own flexible printed circuit to form an FPC component. Each FPC component may include a set of electrical film contacts so that, once the respective FPC components have been fabricated and verified for functionality, the respective FPC components may be electrically and mechanically connected to each other via the film contacts to form the completed FPC module.
It often happens that FPC modules come in pairs for inclusion in the electronic device. For example, where the electronic device is a head mounted display device, a pair of FPC camera modules are needed, one for each eye. In this example, the FPC camera modules may for example be LCoS displays for displaying images to the left and right eyes, or eye tracking cameras for tracking movement of the left and right eyes. In this scenario, although the electronic components used in the respective FPC modules are identical, the FPC components in the first and second FPC modules may be asymmetric.
For example, prior art FIGS. 1A and 1B show a first FPC module 50 including a first FPC component 52 about to be connected to a second FPC component 54 via a first set of electrical film contacts 56 on the components 52, 54. FIGS. 1A and 1B also show a second FPC module 60 including a third FPC component 62 connected to a fourth FPC component 64 via a second set of electrical film contacts 66. The first and third FPC components 52, 62 may be connected in their respective FPC modules at different angles. For example, where the FPC modules 50, 60 are FPC camera modules used in a head mounted display device, the camera modules in the first and third FPC components 52, 62 need to be provided at different angles for the left and right eyes.
Because the electrical film contacts 56 and 66 are different (asymmetric) in the first and second FPC module 50, 60, four separate parts are required when fabricating the pair of FPC modules 50, 60: parts 52, 54, 62, 64. In addition to requiring separate parts, separate tooling is required to fabricate each part.